The latest New Hampshire poll shows Donald Trump continuing to lead, but the latest national poll by Public Policy Polling (a Democratic pollster) shows a huge drop in Trump’s support and a statistical dead heat between the three top contenders: Trump at 24 percent, Ted Cruz at 21 percent, and Marco Rubio at 21 percent — all within the margin of error of 4 percent.

PPP reports:

Rubio is the candidate with the real momentum in the race. He’s up 8 points from his 13% standing in our poll right before Christmas. Beyond that he’s seen a large spike in his favorability rating- it’s improved a net 28 points from +15 at 49/34 to +43 at 64/21. That ties him with Ben Carson as being the most broadly popular candidate on the Republican side.

Things also bode well for Rubio as the field gets smaller in the coming weeks. In a four candidate field he gets 32% to 31% for Trump, 23% for Cruz, and 8% for Bush. In a three candidate field he gets 34% to 33% for Trump and 25% for Cruz. And in head to heads he leads both Trump (52/40) and Cruz (46/40). As other candidates drop out of the race Rubio is the most likely destination of their supporters.

Cruz is actually pretty steady in his national standing even after his surprise victory in Iowa. His 21% standing is up just slightly from 18% in December and his favorability rating is basically unchanged- it was 59/27 then and it’s 58/28 now. One thing Cruz has going for him is that when you combine first and second choices he comes out ahead with 41% to 36% for Rubio, and 32% for Trump. That’s another metric indicating the difficulty Trump may have in growing his support. Additionally Trump trails Cruz 47/41 head to head, which bodes poorly for him if they end up being the finalists.

The race continues to be very fluid. Only 50% of voters say they’re firmly committed to their current candidate choice with the other 50% saying they’re open to changing their minds between now and the election.

Maggie Gallagher is a senior fellow at the American Principles Project.